The 2008 Financial Crisis
In 2008, the global financial system nearly collapsed.
Banks in the US had been lending money recklessly — giving out mortgages to people who couldn't repay them, then packaging those bad loans and selling them as safe investments. When it all unravelled, banks failed, millions of people lost their homes, and governments stepped in to bail out the very institutions that caused the crash.
Ordinary people paid the price. The banks were saved.
For many, this moment made one thing crystal clear: the financial system runs on trust — and that trust had been badly broken.
The Problem with Traditional Money
When you put money in a bank, you're trusting the bank to keep it safe, process your transactions honestly, and not take risks with your savings.
When you send money internationally, you're trusting a chain of intermediaries — each one taking a fee, each one with the power to delay, block, or reverse your transfer.
When a government needs money, it can simply print more — quietly reducing the value of every pound or dollar you already hold.
In every case, you are not in control. Someone else is.
Enter Satoshi Nakamoto
In October 2008 — right in the middle of the financial crisis — an anonymous person (or group) using the name Satoshi Nakamoto published a whitepaper titled "Bitcoin: A Peer-to-Peer Electronic Cash System."
The idea was simple but radical: what if two people could send money directly to each other, without any bank or institution in the middle?
No middleman. No permission needed. No single point of failure.
This was the birth of cryptocurrency.
To this day, nobody knows who Satoshi really is. The identity has never been confirmed — making Bitcoin the only major financial system whose creator simply walked away and disappeared.
So What Actually is a Cryptocurrency?
A cryptocurrency is digital money that runs on a decentralised network — meaning no single bank, company, or government controls it.
Instead of a bank keeping a ledger of who owns what, the record is kept simultaneously by thousands of computers around the world. Everyone can verify it. Nobody can manipulate it alone.
The "crypto" in cryptocurrency refers to cryptography — the mathematics that secures every transaction and makes the system tamper-proof.
Why Does it Have Value?
This is the question everyone asks — and it's a fair one.
The short answer: because people agree it does.
That sounds circular, but it's actually true of all money. A £20 note is a piece of paper. It has value because everyone in the UK agrees it does, and because the government backs it. Remove that agreement and it's worthless.
Cryptocurrency works the same way — except instead of a government backing it, the value comes from the network itself: the code, the scarcity, the security, and the growing number of people who use and trust it.
Bitcoin, for example, will only ever have 21 million coins in existence. That fixed supply — written into the code and unchangeable — is part of what gives it value.
Not Just Bitcoin
Bitcoin was the first cryptocurrency, but thousands have followed.
Some are designed as currency (fast, cheap transactions). Some are platforms for building applications (like Ethereum). Some are pegged to real currencies to avoid volatility (called stablecoins). Some are experiments, some are scams, and some are genuinely solving real problems.
The word "cryptocurrency" covers all of them — but Bitcoin remains the original, the largest, and the one that started it all.
The Bigger Picture
Cryptocurrency isn't just about money. It's about who controls money.
For the first time in history, it's possible to store and transfer value without asking anyone's permission — without a bank account, without a government, without borders.
That's a genuinely new idea. Whether it changes the world or stays niche, understanding it means understanding one of the most important debates happening in finance right now.
Part of the Bitcoin & Blockchain beginner series on whatitis.dev/insights.
Up next in the series
How Does a Blockchain Actually Work? (Blocks, Chains, and the Magic in Between)
The next step in the mental model: how blocks link into a chain, what hashing does for integrity, and how the network agrees on one history — without a bank in the middle.